Control device and parts therefor or the like



Oct. 3, 1967 J. R. WILLSON 3,344,989

CONTROL DEVICE AND PARTS THEREFOR OR THE LIKE Filed Dec. 2, 1964 4Sheets-Sheet l INVENTOR. 1 JAMES R. WILLSON' HIS ATTORNEYS Oct. 3, 1967J. R. RWILLSON 3,344,989

CONTROL. DEVICE AND PARTS THEREFOR OR THE LIKE Filed Dec. 2, 1964 4Sheets-Sheet 2 INVENTOR. JAMES R. WILLSON HIS ATTORNEYS CONTROL DEVICEAND PARTS THEREFOR 'oR THE LIKE J. R. WILLSON Oct. 1967 4 Sheets-Sheet5' Filed Dec.

mac \S. 7

INVENTOR. JAMES RWILLSON WFM HIS ATTORNEYS Oct. 3, 1967 J. R. WILLSON'3I,344,939

CONTROL DEVICE AND PARTS THEREFOR OR THE LIKE Filed Dec. 2, 1964 -4Sheets-Sheet 4 OOOOOOOOOOOOOOOO INVENTOR. JAMES R. WPLLSON HIS ATTORNEYSv United States Patent Ofiice 3,344,989 CONTROL DEVICE AND PARTSTHEREFOR OR THE LIKE James R. Willson, Greensburg, Pa., assignor toRobertshaw Controls Company, Richmond, Va., a corporation of DelawareFiled Dec. 2, 1964, Ser. No. 415,265 10 Claims. (Cl. 236-99) Thisinvention relates to an improved control device for fuel burningapparatus and the like as well as to improved parts for such a controldevice or the like.

-In particular, this invention provides a control device wherein fuel to-a main burner means is cycled on and off in relation to fuel beingsupplied to a pilot burner means disposed adjacent the main burnermeans, the pilot burner means having the flame thereof controlled by thetemperature elfect produced by the main burner means.

Further, this invention provides such a control device wherein the partsthereof are relatively simple to manufacture and assemble together toprovide an economical control device to produce the above function.

In addition, this invention provides such a control device wherein thecontroller pilot burner means can have a standby flame thereof adjustedfor natural gas and can have the heater flame thereof adjusted for LP(liquefied petroleum) gas in a manner hereinafter described.

Accordingly, it is an object of this invention to provide an improvedcontrol device having one or more of the novel features set forth aboveor hereinafter shown or described.

Another object of this invention is to provide improved parts for such acontrol device or the like.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

FIGURE 1 is a schematic view illustrating the improved control system ofthis invention.

FIGURE 2 is an enlarge-d, cross-sectional view of the control deviceillustrated in FIGURE 1.

FIGURE 3 is an exploded perspective view of certain parts of the controldevice illustrated in FIGURE 2.

FIGURE 4 is a cross-sectional view taken on line 44 of FIGURE 2.

FIGURE 5 is a schematic view illustrating the control system illustratedin FIGURE 1 in schematic form.

FIGURE 6 is an enlarged, fragmentary, cross-sectional view taken on line66 of FIGURE 5.

FIGURES 6A-6D are, respectively, views similar to FIGURE 6 andillustrate the pilot adjusting key in different positions thereof.

FIGURE 7 is an enlarged, fragmentary, cross-sectional view taken on line7--7 of FIGURE 5.

FIGURES 7A-7D are, respectively, views similar to FIGURE 7 andillustrate the pilot adjusting key in different operating positionsthereof.

FIGURE 8 is a top view of the controller pilot illustrated in FIGURE 1.

FIGURE 9 is a cross-sectional view taken on line 9-9 of FIGURE 8.

While the various features of this invention are hereinafter describedand illustrated as being particularly adapted to provide control meansfor a cooking oven of a cooking apparatus or the like, it is to beunderstood that 3,344,989 Patented Oct. 3, 1967 the various features ofthis invention can be utilized singly or in any combination thereof toprovide control devices for other structures as desired.

Therefore, this invention is not to be limited to only the embodimentsillustrated in the drawings, because the drawings are merely utilized toillustrate one of the wide variety of uses of this invention.

Referring now to FIGURES 1 and 5, the improved control system of thisinvention is generally indicated by the reference numeral 10 andcomprises a control device 11 for controlling the temperature effect ofan oven (not shown) by means of a main burner means 12 disposed in theoven in any suitable manner.

Fuel is adapted to flow from a supply conduit 13, FIG- URE 5, throughthe control device 11 and out through an outlet conduit 14 thereof to aninlet chamber 15 of an automatic safety valve means 16, the inletchamber 1'5 of the valve means 16 being separated from an outlet chamber17 thereof by a valve seat 18 opened and closed by a valve member 19.

The outlet chamber 17 of the safety valve 16 is interconnected to themain burner means 12 by-a conduit means 20.

Fuel is also adapted to flow from the source 13 through the controldevice F1 in a manner hereinafter described to be interconnected to acontroller pilot burner means 21 by means of a conduit 22, the pilotburner means 21 adapted to always have a small flame 23 except when anincreased flow of fuel through the conduit means 22 takes place in amanner hereinafter described to provide a large flame 24 to ignite fuelsubsequently issuing from the main burner means 12 in the mannerhereinafter described.

When the large flame 24 appears at the controller pilot burner means 21,the same is adapted to heat a temperature sensing bulb 25 which controlsmovement of a movable wall 26 of a temperature responsive device 27' sothat when the temperature sensing bulb 25 senses the large flame 24, themovable wall 26 of the temperature responsive device 27' will operatesuitable levers in the safety valve 16 to snap the valve member 19 toits open position so that fuel can issue to the main burner means 12 andbe ignited by the flame 24. However, when the large flame 24 ceases toexist at the controller pilot burner means 21 and only the small flame23- is issuing therefrom, the condition responsive means 27 moves themovable wall 26 in such a manner that the lever means interconnectingthe movable wall 26 with the valve member 19 snaps the valve member 19to its closed position whereby fuel cannot issue from the main burnermeans 12 until the temperature sensing bulb 25 again senses a largeflame 24 at the controller pilot burner means 21.

The control device 11 of this invention is so constructed and arrangedthat the same is adapted to sense the temperature elfect produced by theburner means 12 so that for any selected temperature position of thecontrol device 1-1, the control device 11 will maintain the oven at thatselected temperature by cycling on and off the burner means 12 by meansof controlling the pilot burner means 21 in a manner hereinafterdescribed.

As illustrated in FIGURES 2 and 5, the control device 11 includes ahousing means 27 formed of three parts 28, Q9 and 30 suitablyinterconnected together in the manner illustrated in FIGURE 2. Thehousing part 29 has a flat surface 31 interrupted by a pair of adjacentports 32 and 33 with the port 32 being interconnected to the fuelmanifold 13 by a passage means 34 and the port 33 being interconnectedto a chamber 35 by a passage means 36 formed in the housing part 29.

A rotatably mounted valve member 37 has a flat surface 38 thereofdisposed in sealing and sliding contact with the surface 31 of thehousing part 29, the valve member 37 having :a recess 39 formed in theside 38 thereof to interconnect together the ports 32 and 33 when thevalve member 37 is moved to a particular rotational position thereof bya control knob 40.

The control knob 40 is interconnected to a plate-like member 41 by aC-shaped shaft 42, the plate-like member 41 being secured to aplate-like member 43 affixed to a hollow tubular member 44 threadedlyreceived in a threaded bore of a hollow tubular member 45 fixed to thehousing part 28. A drive member 46 is openatively interconnected to thevalve member 37 and is operatively interconnected to the drive plate 41when the control knob 40 is first moved from its off position toward anon positionthereof whereby rotational movement of the control knob 40also rotates the valve member 37 to fully interconnect the ports 32 and33. However, the drive plate 41 is disengaged from the drive member 46after the ports 32 and 33 have been fully interconnected by the valvemember 37 whereby the control knob 40 can be rotated in a highertemperature direction to select the desired temperature for the oven orthe like. When the control knob 40 is rotated in the opposite directionback to its off position, the drive plate 41 is again interconnected tothe drive member 46 to rotate the valve 37 back to its off positionwhereby the ports 32 and 33 are not interconnected together.

The hollow tubular member 44 carries an adjusting screw 47 which abutsagainst an end 48 of a fulcrum pin 49 disposed for axial movement in abore 50 in the housing part 29, the pin 49 having a rounded end 51provided with a reduced cylindrical portion 52 received in an aperture53 of a lever 54 disposed in the outlet chamber 35 for a purposehereinafter described.

The passage 36 is sepanated from the chamber 35 by a valve seat 55adapted to be opened and closed by a valve member 56 carried on anextension 57 of a temperature responsive device 58. The temperatureresponsive device 58 has a wall 59 fixed to the housing part 30 and amovable wall 60 carrying the extension 57 for moving the valve member 56toward and away from the valve seat 55 in relation to the temperaturesensed by a temperature sensing bulb 61 disposed in the oven andinterconnected to the interior of the tempenature responsive device 58by a conduit means 62.

As illustrated in FIGURES 2 and 3, the lever 54 has the end 63 thereofprovided with an angled portion 64 having a slot 65 passing therethroughand receiving the extension 57 whereby the portion 64 can bear againstthe movable wall 60 of the temperature responsive device 58 for apurpose hereinafter described.

A valve seat member 66 is disposed in a bore 67 formed in the housingpart 29 and sealed therein by an O ring 68, the valve seat member 66defining an opening 69 therethrough. A ball valve 70 is urged to closethe valve seat opening 69 by a compression spring '71 disposed betweenthe ball valve 70 and a wall 72 of the housing part 29 in the mannerillustrated in FIGURE 2.

The end 73 of the lever 54 has a projection 74 aifixed thereto in anysuitable manner, the projection 74 having an end 75 adapted to engagethe ball valve 70 and having an annular outwardly directed shoulder 76.

A flexible diaphragm 77 is provided and has an outer periphery 78disposed in a recess 79 of the housing part 29 and held in sealingrelationship therewith by a compression spring 80 disposed between thediaphragm '77 and the end 73 of the lever 54.

The central portion of the flexible diaphragm 77 has an opening 81passing therethrough and through which the projection 74 is snap fittedso that the flexible diaphragm 77 cooperates with the housing part 29 todefine an inlet chamber 82 on one side of the valve seat member 66.

As illustrated in FIGURE 5, the inlet chamber 82 is interconnected tothe manifold 13 by a passageway 83 opened and closed by the valve member37. Thus, when the valve member 37 is disposed in its closed position,no fuel can issue from the manifold 13 to the passage 36 or 83. However,when the main valve 37 is moved to an on position thereof, the sameinterconnects the fuel manifold 13 to both the passageway 36 and thepassageway 83 for a purpose hereinafter described.

The outlet chamber 67 on the downstream side of the,

valve seat 66 is interconnected to a pair of branch passageways 84 and85 by a passageway 86 formed in the housing means 27 in the mannerillustrated in FIGURE 5, the branch passageways 84 and 85 respectivelyleading to a bore 87 formed in the housing means 27 and receiving apilot adjusting key or member 88 accessible from the exterior of thedevice 11. The branch passageway 85 has an orifice means 89 disposedtherein for controlling low pressure gas in a manner hereinafterdescribed.

The adjusting key 88 has an axial bore 90 formed therein and beingdisposed in communication with a passageway 91 formed in the housingmeans 27 and leading to the conduit 22 in the manner illustrated in FIG-URE 5. The adjusting key 88 has a pair of transverse bores 92 and 93formed therein in opposite directions and interconnecting the exteriorof the key 88 with the internal bore 90 therein, the transverse bores 92and 93 being alignable with the branch passageways 84 and 85 in a mannerhereinafter described.

Another passageway 94 is formed in the housing means 27 and leads fromthe fuel supply passageway 34 at a point upstream from the valve means37 to a pair of branch passageways 95 and 96 respectively alignable withthe transverse bores 92 and 93 of the adjusting key 88 for a purposehereinafter described. The passageway 94 passes through a suitable fuelfiltering chamber 97 and has a natural gas orifice 98 disposed therein,the branch passageway 95 having a LP (liquefied petroleum) gas orifice99 provided therein.

If desired, the fuel filtering chamber 97 can be interconnected to apair of outlet ports 100 and 101 formed in the housing means 27 by apassage means 102 whereby the outlet ports 100 and 101 can beinterconnected to the pilot burners for the top burners of the cookingapparatus or the like utilizing the control device 11, the passageway102 having a flow adjusting key 103 disposed therein.

The controller pilot burner 21 as illustrated in FIG- URES 1, 8 and 9includes a bent conduit 104 having an outlet end 105 partiallyobstructed by a tang 106 whereby the elbow 107 in the conduit 104 andthe tang 106 provide a turbulence of the fuel flowing out of the conduitend 105 to thoroughly mix the gas and air for proper ignition thereof. Aflame shield 108 is provided and has an opening 109 through which thesmall flame 23 can burn. However, the flame shield 108 extends inalignment with the outlet end 105 to direct an increased flow of fuelout of the outlet end 105 downwardly to the free end 110 of the flameshield 108 so that the large flame 24 will be at the free end 110 of theflame shield 108 when an increased flow of fuel is provided through theconduit 104 in a manner hereinafter described.

The temperature sensing bulb 25 is carried by a pair of ears 111 and 112of the flame shield 108 and is disposed transversely to the flow of fuelbeyond the end 110 of the flame shield 108 so that the temperaturesensing bulb 25 can sense when the large flame 24 is burning at thecontroller burner means 21 for the purpose previously described.

The operation of the controller system 10 of this invention will now bedescribed.

When the control system has natural gas being supplied in the manifold13, -it can be seen that even though the valve means 37 is disposed inits off position fuel is adapted to flow through the passage means 94 tothe branch passage means 96 and out through the transverse bore 93 ofthe adjusting screw 88 to the controller pilot 21 when the adjusting key88 is disposed in the position illustrated in FIGURES 5, 6 and 7.

This flow of fuel through the orifice 98 in the above manner permits thepilot burner means 21 to have the small flame 23 continuously burningonce the same is ignited because regardless of the further action of thecontrol device 11, the small flow of fuel to the controller pilot 11remaining constant.

However, since the sources of natural gas vary in different regions ofthe country and the like, the adjusting key 88 can be rotated in theproper direction between the positions illustrated in FIGURES 6, 7 andFIGURES 6A, 7A tovary the interconnection between the transverse bore 93of the adjusting key 88 and the branch passageway 96 to regulate thestandby flame 23 of the controller pilot 21 so thatv the same will notinadvertently control the temperature sensing bulb 25.

When the adjusting key 88 is disposed in the position illustrated inFIGURES 6B and 713, it can be seen that the branch passage 96 isprevented from being in communication with the controller pilot 21 sothat no fuel can issue therefrom until the adjusting key 88 is disposedin one of its operating positions.

With the adjusting key 88 disposed in one of is positions betweenFIGURES 6, 7 and FIGURES 6A, 7A, it can be seen that the standby flame23 at the control pilot 21 will remain constant.

The operator then turns the control knob 40 from its off position towarda desired temperature setting thereof, the initial rotation of thecontrol knob 40 rotating the valve member 37 to interconnect the passage34 with the passages 36 and 83 for a purpose hereinafter described.

As the control knob 40 is being rotated to its selected on position, thetubular member 44 is rotated therewith and, through its threadedrelation with the threaded member 45, moves to the left in FIGURE 2 topermit the fulcrum pin 49 to move to the left therewith as a compression spring 113 is disposed between the end 73 of the lever 54 andthe housing part 30 in the manner illustrated' in FIGURE 2 whereby thefulcrum pin 49 will be disposed in a particular axial position thereofwhen the control knob 40 is set at its selected temperature setting.

At this time, since the temperature sensing bulb 61 is sensing atemperature below the selected temperature, the movable wall 60 thereofis disposed in such a position that the valve member 56 is disposed inan open position and the lever 54 is pivoted in such a manner by thecompression spring 113 that the same opens the ball valve 70 so thatfuel can flow from the passageway 83 to the passageway 86 leading to thebranch passageway 84. Since the adjusting key 88 is disposed somewhereat or between the positions illustrated in FIGURES 6 and 6A, it can beseen that the increased flow of fuel through the passageway 86 will nowenter the transverse bore 92of the adjusting key 88 and be added to theflow of fuel through the transverse bore 93 whereby the increased flowof fuel to the controller pilot burner 21 will causethe large flame 24to exist as long as the ball valve 70 is disposed in an open positionthereof. Since a large flame 24 now exists at the controller pilot 21,the temperature sensing bulb 25 senses the presence of the flame 24 andsnaps open the valve member 19 of the safety valve 16 whereby fuel canflow through the opened valve member 56 and the open valve member 19 tothe main burner means 12 to be ignited by the large flame 24 at thecontroller pilot 21.

The main burner means 12 continues to have fuel directed thereto in theabove manner until the temperature sensing bulb 61 senses that thetemperature of the oven is at or above the temperature selected by thecontrol knob 40 whereby the movable wall 60 of the condition responsivemeans 58 has moved to the left in FIGURE 2 such a distance that the ballvalve 70 is moved to its closed position and terminates the supply offuel to the passageway 86 so that the large flame 24 ceases to exist atthe controller pilot 21 and only the small flame 23 is provided in theabove manner. When the large flame 24 ceases to exist at the controllerpilot 21, the condition responsive means 27 snaps closed the valvemember 19 of the safety valve 16 to terminate the supply of fuel to themain burner means 12.

Thus, should the temperature of the oven again fall below the selectedtemperature, the movable wall 60 of the condition responsive means 58has moved to the right in FIGURE 2 such a distance that the ball valve70 is again opened so that a large flame 24 can exist at the controllerpilot 21 to open the valve member 19 of the safety valve 16 and permitfuel to issue from the main burner means 12.

Thus, it can be seen that the main burner means 12 will be cycledbetween its on and off positions by means of the controller pilot burner21 to maintain the temperature of the oven at the selected temperature.

However, if for some reason the control device 11 is malfunctioning sothat the ball valve 70 will not close when the temperature responsivedevice 58 senses a temperature above the selected temperature and thetemperature of the oven should exceed a safe limit for the oven, themovable wall 64 of the condition responsive means 58 will move to theleft in FIGURE 2 such a distance that the valve member 56 will bedisposed against the valve seat 55 to prevent the flow of fuel to themain burner means 12 if such a runaway condition should ever exist.

When the control knob 40 is disposed in its broil position, the fulcrumpin 49 is axially moved to the left to such a distance that the lever 54will not permit the valve member 70 to be closed until the conditionresponsive means 58 senses a temperature of approximately 650 F. in theoven. However, before the condition responsive means 58 will move thevalve member 70 to the closed position during the broiling operation,the movable wall 60 of the condition responsive means 58 is moved to theleft such a distance that the valve member 56 tends to throttle down theflow of fuel through the valve seat 55 so that the temperature of theoven in its broil position will never tend to exceed approximately 625F. whereby a continuous flame broiling is provided in the oven by thecontrol device 11 of this invention.

However, should a runaway condition exist, the valve member 56 will seatagainst the valve seat 55 to terminate the flow of fuel to main burnermeans 12 in the manner previously described.

When it is desired to turn ofl the control device 11, the control knob40 is rotated toward its off position whereby when the control knob 40approaches its off position, the valve member 37 is rotated to its oifposition to terminate the flow of fuel to the passage means 83 and 36.However, the small flame 23 continues to burn at the controller pilot 21as the passage 94 is not closed.

As the control knob 40 is being rotated to its off position, the samecauses the tubular member 44 to further thread into the tubular member45 to axially move the fulcrum pin 49 to the right in FIGURE 2 to such adistance so that regardless of the temperature being sensed by thetemperature sensing bulb 61, the lever 54 will be disposed in a positionWhere the ball valve 70 will be disposed against the valve seat 66.

Therefore, it can be seen that the control system 10 of this inventionincludes many novel features wherein the control device 11 can berapidly and substantially automatically assembled together to providethe novel arrangement previously described.

When it is desired to utilize the control device 11 with LP gas, theadjusting key 88 is rotated to the position illustrated in FIGURES 6Cand 7C whereby the transverse bore 92 of the adjusting key 88 is incommunication with the passageway 95 and the transverse bore 93 of theadjusting key 88 is disposed in communication with the passageway 85.

In this position of the adjusting key 88, it can be seen that the source13 of LP gas is directed by the passageway 98 through the orifice 99 tothe transverse bore 92 of the adjusting key 88 to flow out thecontroller pilot 21 to produce the small flame 23. When the ball valve70 is subsequently opened to provide the large flame 24 at thecontroller pilot 21 in the manner previously described, it can be seenthat the flow of fuel from the passageway 83 through the opened valveseat 66 is directed by the passage 86 through the LP gas orifice 89 intothe passageway 85 leading to the transverse bore 93 of the adjusting key88 whereby an increased flow of fuel will be directed to the controllerpilot 21 to produce the large flame 24.

Should it be desired to adjust the large flame 24 of the controllerpilot 21 when the LP gas is being utilized, the adjusting key 88 can beadjusted between the positions illustrated in FIGURES 7C and 7D to varythe amount of fuel being supplied through the passageway 85 to thetransverse bore 93 of the adjusting key 88 to control the size of thelarge flame 24.

Thus, it can be seen that the adjusting key 88 is adapted to adjust thesmall or standby flame 23 of the controller pilot 21 when natural gas isbeing utilized and is also adapted to adjust the large flame or heaterflame 24 at the controller pilot 21 when LP gas is being utilized.

For example, a tremendous variation in natural gas pressures makes itnecessary to be able to adjust the standby pilot flame 21 to be able toavoid runaway to broil in high pressure areas and still not overcompromise low pressure performance at the fixed setting. Thus, theadjustment of the key 88 for the natural gas source merely adjusts thestandby flame 21 and not the heater flame 24.

Conversely, LP gas sources do not have the big variation in pressures,so it becomes important to be able to adjust the heater flame 24 fortrailer requirements and the like, the adjustment of the heater flame 24for LP gas taking place without adjustment of the standby flame 21 forLP gas.

Therefore, it can be seen that not only does this invention provide animproved control device and system, but also this invention providesimproved parts for such a control device or system.

While the form of the invention now preferred has been disclosed asrequired by the statutes, other forms may be used, all coming within thescope of the claims which follow.

What is claimed is:

1. In a control system having a main burner means, said system having apilot burner means and a source of fuel, said system having controlmeans for connecting and disconnecting said source of fuel to and fromsaid main burner means, first passage means for interconnecting saidsource of fuel to said pilot burner means to produce a small standbyflame at said pilot burner means, second passage means for additionallyinterconnecting said source of fuel to said pilot burner means toproduce a large heater flame at said pilot burner means, and a singleadjusting means in said passage means for adjusting the flow ratetherethrough to selectively control the size of said standby flame andthe size of said heater flame, said control means disconnecting saidsource of fuel from said 8 main burner means only when a standby flameis burning at said pilot burner means and interconnecting said source offuel to said main burner means when a heater flame is burning at saidpilot burner means.

2. In a control system as set forth in claim 1, a valve means forcontrolling the interconnection of said source of fuel to said adjustingmeans through said second passage means.

3. In a control system having a main burner means, said system having apilot burner means and a source of fuel, said system having controlmeans for connecting and disconnecting said source of fuel to and fromsaid main burner means, first passage means for interconnecting saidsource of fuel to said pilot burner means to produce a small standbyflame at said pilot burner means, second passage means for additionallyinterconnecting said source to fuel to said pilot burner means toproduce a large heater flame at said pilot burner means, and a singleadjusting key in said passage means for adjusting the flow ratetherethrough to selectively control the size of said standby flame andthe size of said heater flame, said control means disconnecting saidsource of fuel from said main burner means when only a standby flame isburning at said pilot burner means and interconnecting said source offuel to said main burner means when a heater flame is burning at saidpilot burner means.

4. In a control system as set forth in claim 3, a valve means forcontrolling the interconnection of said source of fuel to said adjustingkey means through said second passage means.

5. In a control system having a main burner means, said system having apilot burner means and a source of fuel, said system having controlmeans for connecting and disconnecting said source of fuel to and fromsaid main burner means, a housing means having a bore rotatablyreceiving a hollow adjusting key having the interior thereofinterconnected to the exterior thereof by two transverse bores, saidhousing means having means interconnecting said interior of said keywith said pilot burner means, said housing means having first passagemeans for interconnecting said source of fuel to either one of saidbores to produce a small standby flame at said pilot burner means, saidhousing having second passage means for additionally interconnectingsaid source of fuel to either one of said bores to produce a largeheater flame at said pilot burner means, said adjusting key beingadapted to selectively control the size of said standby flame and thesize of said heater flame, said control means disconnecting said sourceof fuel from said main burner means when only a standby flame is burningat said pilot burner means and interconnecting said source of fuel tosaid main burner means when a heater flame is burning at said pilotburner means.

6. In a control system as set forth in claim 5, a thermostaticallyoperated valve means carried by said housing means and disposed in saidsecond passage means between said source of fuel and said adjusting key.

7. In a control system having a main burner means, said system having apilot burner means and a source of fuel, said system having controlmeans for connecting and disconnecting said source of fuel to and fromsaid main burner means, a housing means having a bore rotatablyreceiving a hollow adjusting key having the interior thereofinterconnected to the exterior thereof by two transverse bores, saidhousing means having means interconmeeting said interior of said keywith said pilot burner means, said housing means having first passagemeans for interconnecting said source of fuel to said bore of saidhousing means, said first passage means having a pair of ends each beingselectively alignable with said bores of said key to produce a smallstandby flame at said pilot burner means, said housing means havingsecond passage means for additional interconnecting said source of fuelto said bore of said housing means, said second passage means having apair of ends each being selectively aligntable with said bores of saidkey to produce a large heater flame at said pilot burner means, saidadjusting key being adapted to selectively control the size of saidstandby flame and the size of said heater flame, said control meansdisconnecting said source of fuel from said main burner means when onlya standby flame is burning at said pilot burner means andinterconnecting said source of fuel to said main burner means when aheater flame is burning at said pilot burner means.

8. In a control system as set forth in claim 7, a natural gas orificemeans disposed in said second passage means between said source of fueland said ends thereof.

9. In a control system as set forth in claim 7, an LP gas orifice meansdisposed in one of said ends of said first passage means.

10. In a control system as set forth in claim 7, an LP gas orifice meansdisposed in one of said ends of said second passage means.

References Cited UNITED STATES PATENTS EDWARD J. MICHAEL, PrimaryExaminer.

1. IN A CONTROL SYSTEM HAVING A MAIN BURNER MEANS, SAID SYSTEM HAVING APILOT BURNER MEANS AND A SOURCE OF FUEL, SAID SYSTEM HAVING CONTROLMEANS FOR CONNECTING AND DISCONNECTING SAID SOURCE OF FUEL TO AND FROMSAID MAIN BURNER MEANS, FIRST PASSAGE MEANS FOR INTERCONNECTING SAIDSOURCE OF FUEL TO SAID PILOT BURNER MEANS TO PRODUCE A SMALL STANDBYFLAME AT SAID PILOT BURNER MEANS, SECOND PASSAGE MEANS FOR ADDITIONALLYINTERCONNECTING SAID SOURCE OF FUEL TO SAID PILOT BURNER MEANS TOPRODUCE A LARGE HEATER FLAME AT SAID PILOT BURNER MEANS, AND A SINGLEADJUSTING MEANS IN SAID PASSAGE MEANS FOR ADJUSTING THE FLOW RATETHERETHROUGH TO SELECTIVELY CONTROL THE SIZE OF SAID STANDBY FLAME ANDTHE SIZE OF SAID HEATER FLAME, SAID CONTROL MEANS DISCONNECTING SAIDSOURCE OF FUEL FROM SAID MAIN BURNER MEANS ONLY WHEN A STANDBY FLAME ISBURNING AT SAID PILOT BURNER MEANS AND INTERCONNECTING SAID SOURCE OFFUEL TO SAID MAIN BURNER MEANS WHEN A HEATER FLAME IS BURNING AT SAIDPILOT BURNER MEANS.